Aurora Substorm

It is real time motion! NOT time-lapse.
Brighter the Aurora, faster the movement.
Yellowknife, Canada.
Captured between 2013.3.1. 22:25 ~23:50
I used Nikon D4, at ISO 6400.
24mm f/1.4G lens at f/2.0 or f/1.4.
I also tested Canon 5D mark III same time.
But Nikon D4 was absolutely winner.
Canon 1Dx may have similar quality. (have similar sensor pixel size)
ps)
All the people are standing and watching aurora.
But one guy is running around.